Of interest in the manufacture of cumene hydroperoxide from cumene are U.S. Pat. Nos. 2,547,938, 2,706,708, 2,722,506, and 3,049,477, all of which relate primarily to the concentration of CHP in a manufacturing process to obtain a product which is more or less of the composition of our starting material. Of particular note may be the steps followed in the example in U.S. Pat. No. 3,049,477, which include the use of a climbing film evaporator. Of perhaps more relevance to our objectives are U.S. Pat. Nos. 2,735,871 and 3,519,690, which are directed to purifying a concentrated CHP stream; however, the approaches used by the inventors are completely different from ours.